diff --git a/libguile/deprecated.h b/libguile/deprecated.h
index fed5bc94b..2cc495432 100644
--- a/libguile/deprecated.h
+++ b/libguile/deprecated.h
@@ -120,6 +120,8 @@ SCM_DEPRECATED SCM scm_regexp_exec (SCM rx, SCM str, SCM start, SCM flags);
 #define SCM_RGXP(X)	(scm_is_true (scm_regexp_p (x)))
 #define SCM_VALIDATE_RGXP(pos, a) SCM_MAKE_VALIDATE_MSG (pos, a, RGXP, "regexp")
 
+#define SCM_VALIDATE_PAIR(cell, expr) SCM_VALIDATE_PAIR__Gone__Inline_second_argument_at_use
+
 /* Deprecated declarations go here.  */
 
 void scm_i_init_deprecated (void);
diff --git a/libguile/pairs.c b/libguile/pairs.c
index a2c7a7d96..acf6d3e86 100644
--- a/libguile/pairs.c
+++ b/libguile/pairs.c
@@ -28,6 +28,7 @@
 #include "boolean.h"
 #include "gc-internal.h"
 #include "trace.h"
+#include "threads.h"
 #include "gsubr.h"
 
 #include "pairs.h"
@@ -49,26 +50,33 @@ verify (SCM_BITS_DIFFER_IN_EXACTLY_ONE_BIT_POSITION		\
         (SCM_ELISP_NIL_BITS, SCM_EOL_BITS));
 
 
-#if (SCM_DEBUG_PAIR_ACCESSES == 1)
-
-#include "ports.h"
-#include "strings.h"
-
-void scm_error_pair_access (SCM non_pair)
+/* Return a newly allocated pair whose car is @var{x} and whose cdr is
+   @var{y}.  The pair is guaranteed to be different (in the sense of
+   @code{eq?}) from every previously existing object.  */
+SCM
+scm_cons (SCM x, SCM y)
 {
-  static unsigned int running = 0;
-  SCM message = scm_from_utf8_string ("Non-pair accessed with SCM_C[AD]R: `~S'\n");
-
-  if (!running)
-    {
-      running = 1;
-      scm_simple_format (scm_current_error_port (),
-			 message, scm_list_1 (non_pair));
-      abort ();
-    }
+  struct scm_pair *p = scm_allocate_tagged (SCM_I_CURRENT_THREAD, sizeof (*p));
+  p->car = x;
+  p->cdr = y;
+  return scm_from_pair (p);
 }
 
-#endif
+SCM
+scm_car (SCM x)
+{
+  if (SCM_UNLIKELY (!scm_is_pair (x)))
+    scm_wrong_type_arg_msg ("car", 0, x, "pair");
+  return SCM_CAR (x);
+}
+
+SCM
+scm_cdr (SCM x)
+{
+  if (SCM_UNLIKELY (!scm_is_pair (x)))
+    scm_wrong_type_arg_msg ("cdr", 0, x, "pair");
+  return SCM_CDR (x);
+}
 
 SCM 
 scm_cons2 (SCM w, SCM x, SCM y)
diff --git a/libguile/pairs.h b/libguile/pairs.h
index 4bca40368..94d433439 100644
--- a/libguile/pairs.h
+++ b/libguile/pairs.h
@@ -67,11 +67,61 @@
 /* #nil is null. */
 #define scm_is_null(x)		(scm_is_null_or_nil(x))
 
-#define SCM_CAR(x)		(SCM_VALIDATE_PAIR (x, SCM_CELL_OBJECT_0 (x)))
-#define SCM_CDR(x)		(SCM_VALIDATE_PAIR (x, SCM_CELL_OBJECT_1 (x)))
+struct scm_pair
+{
+  SCM car;
+  SCM cdr;
+};
 
-#define SCM_SETCAR(x, v)	(SCM_VALIDATE_PAIR (x, SCM_SET_CELL_OBJECT_0 ((x), (v))))
-#define SCM_SETCDR(x, v)	(SCM_VALIDATE_PAIR (x, SCM_SET_CELL_OBJECT_1 ((x), (v))))
+static inline int
+scm_is_pair (SCM x)
+{
+  return SCM_I_CONSP (x);
+}
+
+static inline struct scm_pair *
+scm_to_pair (SCM x)
+{
+  if (!scm_is_pair (x))
+    abort ();
+  return (struct scm_pair *) SCM_UNPACK_POINTER (x);
+}
+
+static inline SCM
+scm_from_pair (struct scm_pair *pair)
+{
+  return SCM_PACK_POINTER (pair);
+}
+
+static inline SCM
+scm_pair_car (struct scm_pair *pair)
+{
+  return pair->car;
+}
+
+static inline SCM
+scm_pair_cdr (struct scm_pair *pair)
+{
+  return pair->cdr;
+}
+
+static inline void
+scm_pair_set_car_x (struct scm_pair *pair, SCM car)
+{
+  pair->car = car;
+}
+
+static inline void
+scm_pair_set_cdr_x (struct scm_pair *pair, SCM cdr)
+{
+  pair->cdr = cdr;
+}
+
+#define SCM_CAR(x) (scm_pair_car (scm_to_pair (x)))
+#define SCM_CDR(x) (scm_pair_cdr (scm_to_pair (x)))
+
+#define SCM_SETCAR(x, v) (scm_pair_set_car_x (scm_to_pair (x), v))
+#define SCM_SETCDR(x, v) (scm_pair_set_cdr_x (scm_to_pair (x), v))
 
 #define SCM_CAAR(OBJ)		SCM_CAR (SCM_CAR (OBJ))
 #define SCM_CDAR(OBJ)		SCM_CDR (SCM_CAR (OBJ))
@@ -116,13 +166,6 @@
 #define SCM_VALIDATE_CONS(pos, scm) \
   SCM_I_MAKE_VALIDATE_MSG2 (pos, scm, scm_is_pair, "pair")
 
-#if (SCM_DEBUG_PAIR_ACCESSES == 1)
-# define SCM_VALIDATE_PAIR(cell, expr) \
-    ((!scm_is_pair (cell) ? scm_error_pair_access (cell), 0 : 0), (expr))
-#else
-# define SCM_VALIDATE_PAIR(cell, expr) (expr)
-#endif
-
 #ifdef BUILDING_LIBGUILE
 #define SCM_VALIDATE_MUTABLE_PAIR(pos, scm) \
   SCM_I_MAKE_VALIDATE_MSG2 (pos, scm, scm_is_mutable_pair, "mutable pair")
@@ -136,68 +179,9 @@
 
 
 
-#if (SCM_DEBUG_PAIR_ACCESSES == 1)
-SCM_API void scm_error_pair_access (SCM);
-#endif
-
-SCM_INLINE int scm_is_pair (SCM x);
-SCM_INLINE SCM scm_cons (SCM x, SCM y);
-SCM_INLINE SCM scm_car (SCM x);
-SCM_INLINE SCM scm_cdr (SCM x);
-
-#if SCM_CAN_INLINE || defined SCM_INLINE_C_IMPLEMENTING_INLINES
-/* Return a newly allocated pair whose car is @var{x} and whose cdr is
-   @var{y}.  The pair is guaranteed to be different (in the sense of
-   @code{eq?}) from every previously existing object.  */
-SCM_INLINE_IMPLEMENTATION SCM
-scm_cons (SCM x, SCM y)
-{
-  return scm_cell (SCM_UNPACK (x), SCM_UNPACK (y));
-}
-
-SCM_INLINE_IMPLEMENTATION int
-scm_is_pair (SCM x)
-{
-  /* The following "workaround_for_gcc_295" avoids bad code generated by
-     i386 gcc 2.95.4 (the Debian packaged 2.95.4-24 at least).
-
-     Under the default -O2 the inlined SCM_I_CONSP test gets "optimized" so
-     the fetch of the tag word from x is done before confirming it's a
-     non-immediate (SCM_NIMP).  Needless to say that bombs badly if x is a
-     immediate.  This was seen to afflict scm_srfi1_split_at and something
-     deep in the bowels of ceval().  In both cases segvs resulted from
-     deferencing a random immediate value.  srfi-1.test exposes the problem
-     through a short list, the immediate being SCM_EOL in that case.
-     Something in syntax.test exposed the ceval() problem.
-
-     Just "volatile SCM workaround_for_gcc_295 = lst" is enough to avoid the
-     problem, without even using that variable.  The "w=w" is just to
-     prevent a warning about it being unused.
-     */
-#if defined (__GNUC__) && __GNUC__ == 2 && __GNUC_MINOR__ == 95
-  volatile SCM workaround_for_gcc_295 = x;
-  workaround_for_gcc_295 = workaround_for_gcc_295;
-#endif
-
-  return SCM_I_CONSP (x);
-}
-
-SCM_INLINE_IMPLEMENTATION SCM
-scm_car (SCM x)
-{
-  if (SCM_UNLIKELY (!scm_is_pair (x)))
-    scm_wrong_type_arg_msg ("car", 0, x, "pair");
-  return SCM_CAR (x);
-}
-
-SCM_INLINE_IMPLEMENTATION SCM
-scm_cdr (SCM x)
-{
-  if (SCM_UNLIKELY (!scm_is_pair (x)))
-    scm_wrong_type_arg_msg ("cdr", 0, x, "pair");
-  return SCM_CDR (x);
-}
-#endif
+SCM_API SCM scm_cons (SCM x, SCM y);
+SCM_API SCM scm_car (SCM x);
+SCM_API SCM scm_cdr (SCM x);
 
 SCM_INTERNAL int scm_is_mutable_pair (SCM x);
 
diff --git a/libguile/scm.h b/libguile/scm.h
index 38a522602..25a8fee2d 100644
--- a/libguile/scm.h
+++ b/libguile/scm.h
@@ -39,13 +39,6 @@
 #define SCM_DEBUG 0
 #endif
 
-/* If SCM_DEBUG_PAIR_ACCESSES is set to 1, accesses to cons cells will
-   be exhaustively checked.  Note:  If this option is enabled, guile
-   will run slower than normally.  */
-#ifndef SCM_DEBUG_PAIR_ACCESSES
-#define SCM_DEBUG_PAIR_ACCESSES SCM_DEBUG
-#endif
-
 /* If SCM_DEBUG_REST_ARGUMENT is set to 1, functions that take rest
    arguments will check whether the rest arguments are actually passed
    as a proper list.  Otherwise, if SCM_DEBUG_REST_ARGUMENT is 0,